How does power change people?
Power turn people into monsters as shown in Macbeth, where Macbeth has become a power mongering beast who was once a honorable man.

+ at least three major points that support your thesis
- first he had thought killing would be bad, no honor later kills many people without thinking
- later he had believed in the prophecy
4.1.105-114
That will never be.Who can impress the forest, bid the treeUnfix his earthbound root? Sweet bodements! Good!Rebellious dead, rise never till the woodOf Birnam rise, and our high-placed MacbethShall live the lease of nature, pay his breathTo time and mortal custom. Yet my heartThrobs to know one thing. Tell me, if your artCan tell so much: shall Banquo’s issue everReign in this kingdom?
This is his reaction from what the witches say to him about when the throne will be taken from him. He hears it and smirks because he believes that the forest will never reach the top of the hill.

- thought he was invincible like Grendel and was foolish, before was courageous and fought with all he had and was noble